1. Field of the Invention
The present invention is directed to a method for generating a volume dataset of a subject with an X-ray system having an X-ray source and an X-ray receiver.
2. Description of the Prior Art
A volume dataset of a subject can be generated, for example, with a C-arm X-ray device. To this end, the C-arm provided with an X-ray source and an X-ray receiver is moved around its orbital axis or angulation axis by approximately 180° around the subject, whereby a series of 2D projections is recorded. The 2D projections are acquired from projection angles that differ from one another. Using this series of 2D projections of the subject (which can currently include up to 400 2D projections), a volume dataset of the subject is reconstructed with the assistance of a computer device provided with a reconstruction program and with the assistance of projection geometries for the C-arm X-ray device that were previously determined in a calibration process. 3D images or arbitrarily selectable tomograms of the subject can be calculated from the volume dataset and presented on a display device.
Such a volume dataset of a subject can also be generated with a type of system referred to as a bi-plane system, which is understood to be an X-ray device that has two C-arms each having an with X-ray source and an X-ray receiver mounted thereon. The generation of a volume dataset with a bi-plane system ensues such that one C-arm of the bi-plane system is moved out of the working area while the series of 2D projections of the subject is recorded with the other C-arm, and the volume dataset of the subject is reconstructed therefrom. A disadvantage of this technique for bi-plane systems is that the one C-arm must always be moved out of the work area of the bi-plane system for generating a volume dataset, especially in order to avoid possible collisions with the other C-arm during the acquisition of the series of 2D projections. Another disadvantage is the comparatively lone exposure time required for the acquisition of the series of 2D projections, which is especially disadvantageous in the medical field when a contrast agent must be injected into the body of a patient during the acquisition of the 2D projections in order to be able to show specific tissue regions especially well in the 2D projections.